feat: Add host CLI option as alternative to config (#1395)

Author: tpoliaw

src/blueapi/cli/cli.py

@@ -81,6 +81,19 @@ def is_str_dict(val: Any) -> TypeGuard[TaskParameters]:
     invoke_without_command=True, context_settings={"auto_envvar_prefix": "BLUEAPI"}
 )
 @click.version_option(version=__version__, prog_name="blueapi")
+@click.option(
+    "-h",
+    "--host",
+    type=str,
+    help=textwrap.dedent(
+        """
+        Hostname for the blueapi instance to use
+
+        Value should be the full URL including scheme (and port if non-default),
+        eg `--host http://localhost:8000`
+        """
+    ),
+)
 @click.option(
     "-c", "--config", type=Path, help="Path to configuration YAML file", multiple=True
 )
@@ -100,7 +113,10 @@ def is_str_dict(val: Any) -> TypeGuard[TaskParameters]:
 )
 @click.pass_context
 def main(
-    ctx: click.Context, config: tuple[Path, ...], log_level: str | None = None
+    ctx: click.Context,
+    config: tuple[Path, ...],
+    host: str | None = None,
+    log_level: str | None = None,
 ) -> None:
     # if no command is supplied, run with the options passed
 
@@ -112,7 +128,8 @@ def main(
         config_loader.use_values_from_yaml(*config)
     except FileNotFoundError as fnfe:
         raise ClickException(f"Config file not found: {fnfe.filename}") from fnfe
-
+    if host:
+        config_loader.use_values({"api": {"url": host}})
     if log_level:
         config_loader.use_values({"logging": {"level": log_level}})
 

tests/unit_tests/cli/test_cli.py

@@ -1430,3 +1430,45 @@ def test_log_level_override(flag: str, level: str, runner: CliRunner):
         runner.invoke(main, [flag])
         mock_log.getLogger().setLevel.assert_called_once_with(level)
         mock_log.StreamHandler().setLevel.assert_called_once_with(level)
+
+
+@responses.activate
+def test_host_option(runner: CliRunner):
+    response = responses.add(
+        responses.GET,
+        "http://override.example.com:5678/plans",
+        json={"plans": []},
+        status=200,
+    )
+
+    res = runner.invoke(
+        main,
+        ["--host", "http://override.example.com:5678", "controller", "plans"],
+    )
+    assert response.call_count == 1
+    assert res.exit_code == 0
+
+
+@responses.activate
+def test_host_overrides_config(runner: CliRunner):
+    config_path = "tests/unit_tests/example_yaml/rest_config.yaml"
+    response = responses.add(
+        responses.GET,
+        "http://override.example.com:5678/plans",
+        json={"plans": []},
+        status=200,
+    )
+
+    res = runner.invoke(
+        main,
+        [
+            "--host",
+            "http://override.example.com:5678",
+            "--config",
+            config_path,
+            "controller",
+            "plans",
+        ],
+    )
+    assert response.call_count == 1
+    assert res.exit_code == 0